Testing an impure function

[finnhodgkin]

The functions you are testing in backendScript currently rely on external data. This means that if you add data to your database at a later time it could cause your tests to fail unexpectedly. They could quite easily be converted to pure functions and then tested in a more structured, scale-able way. For example the suggest function:

function suggest(sugName) {
  var result = dbKeys.filter(function(item) {
    return item.startsWith(sugName);
  });
  return result;
}

Could be converted to:

function suggest(sugName, searchArray) {
  var result = searchArray.filter(function(item) {
    return item.startsWith(sugName);
  });
  return result;
}

Although this makes the function slightly harder to call, it allows easy exchanging of data: you could swap the database to an array of words and the function wouldn't break.

[finnhodgkin]

Currently if you added a colour 'redish' to the list, it would make tests fail.